Molecular cloning and characterization of a metal responsive Aedes aegyptiintestinal mucin cDNA

We have isolated a cDNA from Aedes aegypti that is transcribed in the larva l midgut in response to metal exposure, and in the adult female midgut in r esponse to iron or cadmium exposure, or a blood meal. The cDNA encodes a pr otein, designated Aedes aegypti intestinal mucin 1 (AEIMUC1), which has sim ilarities with invertebrate intestinal mucins and peritrophins, and vertebr ate mucins. Proline, serine and threonine comprise 30% of the amino acid co mposition of AEIMUC1, a characteristic of mucins. AEIMUC1 contains three cy steine-rich domains, two of which flank a proline/serine/threonine-rich dom ain, a feature shared by many mucin genes. This is the first report on the isolation of a metal-responsive gene from an aquatic insect.